1. Technical Field
The present invention generally pertains to motor vehicles. More particular, the present invention pertains to a method and apparatus for servicing an internal combustion engine. More specifically, but without restriction to the particular embodiment and/or use which is shown and described for purposes of illustration, the present invention relates to a method and apparatus for maintaining cam sprocket alignment while the cam shaft of an engine is removed for servicing the engine.
2. Discussion
In a conventional motor vehicle having an internal combustion engine, a cam shaft is rotatably mounted in a cylinder head. The cylinder head includes a plurality of journals longitudinally spaced along its length. The journals define a cam shaft axis and support the cam shaft. A cam sprocket is fixedly attached to the cam shaft. The cam sprocket is coupled to a rotational output of the internal combustion engine through a tension chain.
When it is necessary to service the cylinder head, it is frequently necessary to remove the cam shaft. For example, access to the cylinder heads and cylinders of the internal combustion engine is restricted, if not prevented, unless the cam shaft is removed. When the cam shaft is conventionally removed, the radial position of the cam sprocket is altered and proper tensioning of the tension chain is disturbed. As a result, it is often necessary to recalibrate the tension chain. This process is extremely time consuming as it typically involves removal of the oil pan and the front chain case cover.
Thus, it is would be desirable to remove a cam shaft from the cylinder head of an internal combustion engine while maintaining proper radial alignment of the cam sprocket.